// Copyright 2011 Hunter Freyer
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package languish.base;

import java.util.Arrays;
import java.util.List;

public final class Term {

  private final Operation operation;
  private final List<?> args;

  public Operation getOperation() {
    return operation;
  }

  public List<?> getArgs() {
    return args;
  }

  public Object getFirst() {
    return args.get(0);
  }

  public Object getSecond() {
    return args.get(1);
  }

  public static Term of(Operation operation, Object... args) {
    return new Term(operation, Arrays.asList(args));
  }

  public Term(Operation operation, List<?> args) {
    super();
    this.operation = operation;
    this.args = args;
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((args == null) ? 0 : args.hashCode());
    result = prime * result + ((operation == null) ? 0 : operation.hashCode());
    return result;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj)
      return true;
    if (obj == null)
      return false;
    if (getClass() != obj.getClass())
      return false;
    Term other = (Term) obj;
    if (args == null) {
      if (other.args != null)
        return false;
    } else if (!args.equals(other.args))
      return false;
    if (operation == null) {
      if (other.operation != null)
        return false;
    } else if (!operation.equals(other.operation))
      return false;
    return true;
  }

  @Override
  public String toString() {
    return "[ " + operation + " args=" + args + "]";
  }
}
